The present invention relates to a tank insert which can be inserted into an opening in a fuel tank and which bears a fuel feed device and/or a level indicator by means of a holder which closes the opening, the tank insert being furthermore provided with a pressure sensor.
Recently, the recognition of leaks in fuel systems of automotive vehicles has become of increasing importance. Leaks can arise, for instance, in the line connections due to defective connections or else due to stones in the tank itself, or they may occur after the filling of the tank if one forgets to screw the gas cap onto the opening of the tank. Leaks in the fuel system can lead to fuel coming against hot parts of the vehicle and igniting. It is also dangerous if, for instance diesel fuel can drip onto the road as the result of a leak, since there is then the danger of skidding, which is particularly critical for motorcyclists. Environmental aspects also make a dependable monitoring of the tightness of fuel systems necessary.
Leakages in fuel systems can be recognized by measurement of the pressure on the spot with the use of suitable evaluation algorithms. For example, the fuel tank can be subjected to pressure or vacuum when the vehicle is at a standstill and before it is started, and it can then be determined by means of a pressure sensor whether, after a disconnecting of the fuel tank from a source of pressure fluid under pressure or vacuum, whether this pressure remains constant in the fuel tank. If not, then a leak must be present. However, the arrangement of the pressure sensor is problematical here, since due to it, there is additionally a danger of leaks and a danger of the emission of fuel from the line leading to the pressure sensor.